Use of high energy nitrate derivatives of various polyhydroxy alcohols are known in the high explosives and propellant arts, particularly as energetic organic plasticizers for cross-linked double based rocket propellant compositions.
Because of the vulnerability of rocket propellant materials to low temperature extremes, particularly the tendency of double based solid propellants to become embrittled and to crack, causing irregular burning properties, it is found useful to incorporate mixed energetic organic plasticizers to prevent crystallization. By way of example, mixtures of 1, 2, 4-butanetriol trinitrate (BTTN), triethylene glycol dinitrate (TEGDN), nitroglycerine (NG), as well as glycerol glycol ether (GGE) can be used in nitrated form as glycerol glycol ether trinitrate (ROC), for such purpose.
Of the above compounds, however, the nitrate derivative of glycerol glycol ether, glycerol glycol ether trinitrate (ROC) in combination with nitroglycerine (NG), is found particularly suitable because of its high energy content and low volatility. Such composition, however, is expensive and time consuming to safely produce by traditional conitration reaction. This is so because of the need to separate out or purify the primary GGE intermediate product to eliminate sodium chloride and minimize ethylene glycol content which, respectively, cause corrosion and production of a volatile dinitrate in the nitrator.
A frequently used art process for obtaining GGE (i.e. Kharasch synthesis) is generally represented by the following reaction: ##STR1##
A number of by-products are obtained by this process, and the required distillation steps to obtain GGE are further complicated by precipitation of dissolved salts from the hydrolysis step.
It is an object of the present invention to produce high energy plasticizer composition suitable for cross-linked double based rocket propellant.
It is a further object of the present invention to cheaply and efficiently produce high energy plasticizer composition comprising glycerol glycol ether trinitrate and nitroglycerine in controlled ratios and with predictable stability using glycerol and ethylene oxide as raw material.